The present invention relates to a cordless telephone system wherein a base unit connected to a subscriber line establishes radio frequency links with at least one mobile unit and, more particularly, to a cordless telephone system wherein a speech communication link established between a user of a mobile unit and another party by way of the subscriber line and the radio link may not be monitored by the user of a base unit or the user of a branch telephone connected to the base unit without automatically notifying the user of the mobile unit.